Terpenes and terpenoids encompass one of the most extensive
and valuable classes of secondary metabolites. Their ten-carbon-containing
oxygenated representatives, monoterpenoids, are the main components of plant
essential oils, being widely exploited in the cosmetic, pharmaceutical, and food
industrial areas. Due to its widespread use, it is crucial to investigate their
environmental distribution. Thus, new water solubility data were obtained for
six monoterpenoids ((1R)-(+)-camphor, (S)-(+)-carvone, eucalyptol, (1R)-
(−)-fenchone, L-(−)-menthol, and (−)-menthone) at 298.2 and 313.2 K.
Furthermore, octanol−water partition coefficients of 12 monoterpenoids (the
six mentioned above plus carvacrol, (±)-β-citronellol, eugenol, geraniol, linalool,
and thymol) were measured at 298.2 K. The COSMO-RS thermodynamic
model and other more empirical approaches were evaluated for the description
of the solubilities and partition coefficients, showing reliable predictions. Lastly, the distribution of the monoterpenoids in the
different environmental compartments was assessed through an intuitive two-dimensional chemical space diagram based on the
physicochemical equilibrium information reported.
This work was developed within the scope of the project
CIMO-Mountain Research Center, UIDB/00690/2020, and
CICECO-Aveiro Institute of Materials, UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through
the Portuguese Foundation for Science and Technology
(FCT)/MCTES. S.M.V.-B. thanks FCT and the European
Social Fund (ESF) for his Ph.D. grant (SFRH/BD/138149/2018). M.C.d.C. would also like to thank CNPq (306666/
2020-0) and FAPESP (2014/21252-0).
